Masimo
MASI
MASI was delisted on the 9th of June, 2026.
326 hedge funds and large institutions have $3.85B invested in Masimo in 2018 Q1 according to their latest regulatory filings, with 51 funds opening new positions, 112 increasing their positions, 116 reducing their positions, and 56 closing their positions.
25% more call options, than puts
Call options by funds: $14M | Put options by funds: $11.2M
5% more capital invested
Capital invested by funds: $3.65B → $3.85B (+$200M)
1.41% more ownership
Funds ownership: 83.26% → 84.67% (+1.4%)
0% more funds holding in top 10
Funds holding in top 10: 1 → 1 (0)
3% less repeat investments, than reductions
Existing positions increased: 112 | Existing positions reduced: 116
9% less first-time investments, than exits
New positions opened: 51 | Existing positions closed: 56
4% less funds holding
Funds holding: 338 → 326 (-12)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Ameriprise
Minneapolis,
Minnesota
|
+$121M |
| 2 |
Citadel Advisors
Miami,
Florida
|
+$82.1M |
| 3 |
Point72 Asset Management
Stamford,
Connecticut
|
+$60.8M |
| 4 |
HM
HealthCor Management
New York
|
+$50.1M |
| 5 |
CIP
Champlain Investment Partners
Burlington,
Vermont
|
+$43.1M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Arrowstreet Capital
Boston,
Massachusetts
|
-$80.3M |
| 2 |
Robeco Institutional Asset Management
Rotterdam,
Netherlands
|
-$77M |
| 3 |
Vanguard Group
Malvern,
Pennsylvania
|
-$63.4M |
| 4 |
Acadian Asset Management
Boston,
Massachusetts
|
-$60.3M |
| 5 |
JP Morgan Chase
New York
|
-$30.4M |
MASI Hedge Fund Activity: Q1 2018 in Review
326 of the 4,364 institutional investors tracked by Wall St. Rank reported a position in Masimo (MASI) for Q1 2018, worth a combined $3.85B — up 5.5% from $3.65B a quarter earlier.
Sellers outnumbered buyers: 56 funds closed out of MASI and 51 opened new positions — a net loss of 5 holders — while 116 trimmed existing stakes and 112 added.
The largest buyer was Ameriprise, adding an estimated $121M. The largest seller was Arrowstreet Capital, cutting an estimated $80.3M.
- 326 institutional investors held Masimo (MASI) as of Q1 2018, down from 338 in Q4 2017.
- Funds reported $3.85B of Masimo stock for Q1 2018, up 5.5% quarter-over-quarter.
- 51 funds opened new Masimo positions in Q1 2018 and 56 closed out, a net change of -5 holders.
- The largest Masimo buyer in Q1 2018 was Ameriprise, an estimated $121M added.
- The largest Masimo seller in Q1 2018 was Arrowstreet Capital, an estimated $80.3M sold.
Based on aggregated 13F filings for Q1 2018.